After reading on these boards for a long time I think you should have an accurate idea of what you are dealing with. You will never get the marriage you had with her before this back. At best this will be a new marriage and the affair will always there in the background. You will never get over this if you stay with this women you will just have to learn to live with it. Her presence will be a constant reminder for a long time.
and read the these peoples posts. This is probably the most accurate picture of what reconciliation is like. Many of these people have been on there for years. Understand that lots of these people and their spouses have been working for years and are still in deep pain.
There is a very good possibly that your wife has some very deep seeded emotional problem or possible mental illness. She will need to work very hard to fix this but first she has to acknowledge it. It won't work if she doesn't. She may never be able to completely fix it so you may have to learn how to live with it to a certain extent.
Right now you are making decisions partly out of great trauma which is understandable, it is probably better to make them after you separate from your wife and detach. Because of what has happened to you you are not in your right mind at this moment. Again this is why it is best to wait. Also unfortunately she may also be making decisions out of guilt and fear as well. Remember in her own words this started as an exit affair. If it's true that she doesn't love you as she said, after the drama of this situation dies down she will probably return to her ****ty ways. Many BS have this happen. I tell you this because at least now you are the one in control of the situation. If she decides to blind side you with divorce or cheat again you may not be the next time. This is a risk you should think about.
Your wife has done a horrible act, something that many people in this world could not do even to their worst enemy. In my mind that makes her a lower class of person. I don't mean status wise, I mean morality wise. Meaning she doesn't have the kind of shame and guilt that the rest of us do. This makes her emotionally dangerous and in my mind more susceptible to doing despicable acts. Make sure you understand that you are choosing to spend the rest of your life with someone who showed you the father of her children a complete and total lack of respect. She very well may be a narcissist. It's better for children to have two homes if one is safe and stable, then one where the stable parent spends all their emotional life consumed with the other who is destructive. If your wife truly is a narcissist or has some other form of mental illness such as borderline personality disorder, at lest if you leave and marry someone else they can see a healthy marriage modeled for them. Remember this is a woman was also capable of lying directly to your face for a long time.
On more question will you be happy about that 5, 10, 15 years from now. So many BS emotionally recover and realize what a terrible deal they took by staying. I tell you this because there is something you will learn is more valuable then even love in this world, TIME. You can fall in love again, there are many people you can fall in love with with. You will never get back the time you invest in this person. I suggest you think long and hard and make sure you are not operating out of fear. Or out of a love for a person who is now dead.
It is natural to want to save your family and wife. But your wife as you knew her is not coming back. The person you are committing to is a very different person now then the one you married. That is not going to change. 30 years from now she will still be the person who ****ed her neighbor in the guest room. Who stabbed you in the back for some tawdry sex. Better to come to terms with that and accept it then wait 30 years thinking the women you married is going to return. I know you want desperately for everything to just go back to the way it was, but it won't. Don't make decisions thinking it will because you will end up disappointed.
I know this is harsh, but it needs to be said. You are accepting a terrible deal. You deserve much better in life. There is much better out there. Look you are going to have to go through the pain no matter what. You may think if you stay together this will make the pain go away faster, but for most it may actually prolong it. So the choice really is -- Go through the pain and end up with the person who caused it. Or go through the pain and end up with the possibility of someone new and a fresh start, without all the garbage, monitoring, fear, triggers, sexual problems and all the rest of it that goes with trying to live your life who did something like this to another human being. You don't have to give up the dream of a faithful partner. But only if you give up this women.